#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int is_prime(int i)
{
	int n = 0;
	for (n = 2; n < i; n++)
	{
		if (i%n == 0)
		{
			return 0;
		}
	}
	return 1;
}
int main()
{
	int i = 100;
	int count = 0;
	for (i = 100; i < 999; i++)
	{
		int ret = is_prime(i);
		if (ret == 1)
		{
			count++;
		}
	}
	printf("%d", count);
	return 0;
}
#include <stdio.h>
int main()
{
	int n = 0;
	scanf("%d", &n);
	if (n % 2 == 1)
	{
		printf("%d %d", (n / 2) + 1, n / 2);
	}
	else
	{
		printf("%d %d", n / 2, n / 2);
	}
	return 0;
}
#include<stdio.h>
int main()
{
	long n = 0;
	scanf("%ld", &n);
	long i = 0;
	long ret = 0;
	for (i = 1; i <= n; i++)
	{
		ret += i;
	}
	printf("%ld", ret);
	return 0;
}
